package _剑指offer._设计模式._观察者模式;





public class Main {
    public static void main(String[] args) {
        Subject subject = new ConcreteSubject();
        Observer ob1 = new ConcreteObserver();
        Observer ob2 = new ConcreteObserver();
        subject.add(ob1);
        subject.add(ob2);
        subject.notifyObserver("hello");
        
    }    
}
